Head Lice Infestation in Pre-High School Girls, Lak Hok Suburban Area, Pathum Thani Province, in Central Thailand.

This is a cross-sectional descriptive survey to determine the prevalence of lice infestation in a pre-high school, Lak Hok subdistrict, Pathum Thani Province, in central part of Thailand. The knowledge, attitudes, and practices of parents/guardians toward head lice in female children during February-April 2020 were evaluated. A total of 83 out of 111 parents (74.8%) agreed to complete consent forms and questionnaires. The prevalence of pediculosis found in this study was 68.7%. The infestation was found in the primary school level (87.5%), which was significantly higher than pre-primary school (29.6%; p < 0.05). Itching scalp was revealed in 93.0% of pediculosis. The results showed that occupation, religion, education, and income showed no significant difference between lice infested and non-infested students (p > 0.05). There was no significant association between sex, occupation, religion, education, income, status of parents, and family size among lice infested and non-infested students (p > 0.05). The parents/guardians showed the middle level of knowledge concerning with pediculosis capitis (66.8%). The lack of knowledge leading, first, to the belief that pediculosis does not need any treatment (89.2%), followed by boys getting head lice more frequently than girls (85.5%), and the belief that sharing infested combs, brushes, or hair ribbons does not result in lice transmission (79.9%). More than 75% of the parents/guardians had experienced infestation of head lice and showed themselves willing and able to diagnose and treat their family. However, 50.6% of them did not feel shame when their children were infested with head lice. Children washing their hair by themselves were found to be a significant factor in infestation (88.5%). High rate of pediculosis in this suburban school needs more intensive care by parents/guardians and teachers. Furthermore, improvement strategies to prevent and control lice in the school need to be more specifically planned and scheduled by teachers and health administrators.

Modified Nonnutrient Agar Plate Culture for the Diagnosis of Strongyloides stercoralis and Hookworm Infections in La-Ngu District, Satun Province, Southern Thailand.

Due to the low prevalence and light intensity of Strongyloides stercoralis (S. stercoralis, Ss) and hookworm (HW) in Thailand, an increase in the efficacy of detection with the appropriate diagnosis is needed. This cross-sectional survey is aimed at using modified nonnutrient agar plate culture (mNNAPC) to assess the prevalence of S. stercoralis and hookworm infections and to report intestinal parasitic infections in La-Ngu villagers, Satun Province in Southern Thailand. We used wet smear, modified Harada-Mori filter paper culture (mHMFPC), and mNNAPC to investigate 204 villagers (4 villages) between August 2016 and January 2017. The combination of mHMFPC and mNNAPC raised the prevalence of S. stercoralis and hookworm infections among the study population from 3.4% and 1.0% to 6.9% and 2.5%, respectively. There were no significant differences between demographic characteristics and these infections (p < 0.05). Three types of protozoal infections, Blastocystis spp. (2.9%), Entamoeba histolytica-like (0.5%), and Giardia duodenalis (0.5%), and 3 species of helminthic infections, S. stercoralis (6.9%) (14 cases), hookworm 2.5%, and Enterobius vermicularis 0.5%, were demonstrated in this area. The mNNAPC showed the highest efficacy in detecting both parasites (Ss 92.9% and HW 80%), whereas the wet smear detected none.

Enteropathogenic Bacterial and Intestinal Parasitic Infections among Asymptomatic Food Handlers in Rangsit University Canteens, Central Thailand.

Food handlers play an important role in the transmission of foodborne diseases. 108 asymptomatic food handlers work in RSU canteens and have never been checked for intestinal bacteria and parasites, which might be a potential source of infection for customers. This study is aimed at estimating the prevalence of enteropathogenic bacterial and intestinal parasitic infections among food handlers in Rangsit University canteens, central Thailand. A total of 79 food handlers were enrolled, and each provided one stool sample (response rate of 73.2%). Females comprised 93.7% of study participants, and the largest age group was 41-50 years (34.2%). The prevalence of enteropathogenic bacteria in stool cultures was 2.5%, and only Aeromonas spp. were detected. The pathogenic protozoa Giardia duodenalis was detected in 1.3% of samples, and nonpathogenic protozoa was found in 11.4%. No helminths were found in any samples. Approximately 80% of food handlers demonstrated good hygiene practices, including regular hand washing after visiting the toilet, regular hand washing when preparing food, using soap when washing hands, wearing uniforms/gowns, practicing correct hand washing techniques, and having short fingernails. However, the results showed a lack of personal hygiene training and routine medical care (>50% of samples). Stronger intervention would help to eliminate future infections.

Pretreatment gametocyte carriage in symptomatic patients with Plasmodium falciparum and Plasmodium vivax infections on the Thai-Myanmar border.

Background&objectives: Changes in parasite biology, particularly the gametocytogenesis process, could be one of the important contributing factors for worldwide malaria resurgence. The present study investigated the prevalence rates of pretreatment gametocyte carriage and density in Plasmodium falciparum and P. vivax infections in the low malaria-endemic area on the Thai-Myanmar border. METHODS: One hundred and twenty-six blood samples were collected from patients with signs and symptoms of malaria who attended malaria clinics. Malaria positive cases detected by microscopic examination were confirmed by species-specific nested-PCR in 97 (29 and 68 samples for P. falciparum and P. vivax, respectively). RESULTS: The proportion of P. vivax and P. falciparum-infected samples was 70.1: 29.9%. The density in P. falciparum positive samples [median (95%CI): 10,340 (5280-19,200) µ/l] was significantly higher than P. vivax positive samples [4508 (3240-6120) µ/l]. Sixteen out of twenty-nine (55.2%) and 36 out of 68 (52.9%) P. falciparum- and P. vivax-infected samples, respectively, were gametocyte-positive. Gametocyte density in the P. falciparum-infected[124 (69-253) /µl] was significantly higher than that of the P. vivax-infected [54 (45-70)/µl] samples. A significant correlation between gametocyte density and pretreatment parasitemia was only detected in P. falciparum-infected, but not P. vivax-infected samples. INTERPRETATION & CONCLUSION: The observed high prevalence rates of pretreatment gametocyte carriage of both malaria species, which serves as a large malaria reservoir, particularly in P. falciparum infection, could have a significant impact on malaria control in the endemic populations.

Modified Harada-Mori and simple wet mount to determine hookworm infections in Yo Island urban area, Songkhla, Southern Thailand.

BACKGROUND: Hookworm was a previously dominant parasitic infection in Southern Thailand. The changing population to an aging society in Yo Island has never been investigated for intestinal parasites. This study aimed to estimate the prevalence of hookworm and intestinal parasitic infections on Yo Island, a small island in Songkhla Province of southern Thailand. METHODS: A cross-sectional study was conducted among volunteers aged 15 and above to give one stool sample that was screened by wet mount for intestinal parasites and the modified Harada-Mori culture (mHMFPC) which is adapted from HMFPC, using local plastic bag containers instead of test tubes for hookworm detection. RESULTS: Two hundred forty-seven volunteers (females = 160) gave one stool. The highest participation was in age group higher than 60 years. Most were Buddhism (89.1%), agriculturist (71.4%), non-education (87.9%), and income lower than 9000 baht (50.2%). The prevalence of intestinal parasites was 13/247 (5.3%) of which 6/247 (2.4%) were positive for hookworm species Necator americanus. One volunteer was coinfected with hookworm and Strongyloides stercoralis and another with Endolimax nana and Blastocystis hominis. The mHMFPC detected more positive stool samples than wet mount and wet mount: 5 vs. 2. CONCLUSIONS: Parasite prevalence was low in this urban community of mostly low-income village dwellers. The mHMFPC appeared better at detecting hookworm but numbers were small. Combined techniques are suitable for field use.

A preliminary epidemiological study of pinworm infection in Thaklong Municipal Early Childhood Development Center and Rangsit Babies' Home, Pathum Thani, Thailand.

OBJECTIVES: We investigated the prevalence and risk factors for Enterobius vermicularis in children at the Thaklong Municipal Early Childhood Development Center (TMECDC), and the Rangsit Babies' Home (RBH) in Pathum Thani, Thailand using the Scotch tape method. RESULTS: 397 children aged 3-6 years were sampled (male = 198); 31 (7.8%) were E. vermicularis positive: 1 (TMECDC) and 30 (RBH). 264/397 (66.50%) of parents had incomes > 12,000 baht/month and 313/397 (78.84%) were educated from primary school to college. Univariate analysis identified (i) age 5-6 years, (ii) female sex, (iii) lower education of mother/father, (iv) being a house wife, (v) being a low income family, (vi) being resident in the orphanage, (vii) reporting anorexia and/or fever, and (viii) not washing their bottoms as factors for a positive slide. By logistic regression, education level and age group were independently associated with a positive Scotch tape result. Older children and higher family education had opposing associations with E. vermicularis. Strategies to control pinworm infection should focus on high-risk children in orphanages.

Intestinal parasitic infections in suburban government schools, Lak Hok subdistrict, Muang Pathum Thani, Thailand.

OBJECTIVE: To provide baseline information of parasitic infections in 3 suburban government schools, Lakhok subdistrict of Muang Pathum Thani, Thailand. METHODS: This study was conducted between May-June 2010 using simple direct smear and modified formalin ether and from a population of 1 253 in 3 suburban government schools. RESULTS: Total samples of 202 registered and participated. The average of prevalence of infection from 3 schools was 13.9%, there were 13.7%, 14.3% and 13.9% in N, S and R school, respectively with no significant difference between schools (P>0.05). The infection rates did not show significant difference between genders (P>0.05). The highest rate of infection was 20.4% in Pathom 2 (8 years) students and the lowest was 4% in Pathom 1 (7 years) with statistically difference between age groups (P<0.05). The highest prevalence of pathogenic protozoa was Giardia lamblia (G. lamblia) which was found in 50% of infected cases, followed by 25% of Entamoeba histolytica (E. histolytica) and Blastocystis hominis (B. hominis). The highest prevalence of non-pathogenic protozoa was Endolimax nana (E. nana) which was found in 88.9%, followed by 11.1% of Entamoeba coli (E. coli). Mixed infections between Blastocystis hominis (B. hominis) and Endolimax nana (E. nana) were reported at 7.1%. The only helminthic infection found in this study area was hookworm, found in 1 student (3.8%). The formalin ether concentration technique showed a higher efficacy of detection (78%-100%) than the simple direct smear method (0%-50%). CONCLUSIONS: Surveillance of Protozoan infections may need to be focused on suburban areas.

Intestinal parasitic infections in Srimum suburban area of Nakhon Ratchasima Province, Thailand.

A survey on intestinal parasitic infections and some risk factors of infection (social, economic and behavioral) was conducted in suburban area at Simum subdistrict, Mueang district, Nakhon Ratchasima Province during the period of April 3rd to April 11th, 2007. A total of 214 stool samples, from 85 males and 129 females were examined using simple direct smear, Kato's thick smear and modified Harada-Mori Filter Paper Strip culture technique. The results showed that the prevalence rate of protozoa infections by simple direct smear method was 17.3% (37 infected samples) in 11 males and 26 females and were from all age groups. Mixed infections (56.8%), showed higher results than single infection. The highest number of intestinal protozoan infections was Entamoeba histolytica (11.7%), followed by Blastocystis hominis (5.6%). Fifty four percent of protozoan infection was at a moderate to high level. Ninety five percent of infected cases consumed unboiled water. The prevalence rate of helminthic infections was 7% total by Kato's thick smear and Modified Harada-Mori Filter Paper Strip culture technique. Kato's Thick smear Technique showed the highest rate of Strongyloides stercolaris (2.8%), followed by hookworm infection (1.4%) Taenia spp. (0.9%), and Enterobius vermicularis (0.5%), respectively. All infections showed a light intensity, (< 200 epg), using Kato-Katz thick smear. Although Modified Harada-Mori's culture Technique showed higher S. stercolaris (3.3%) and hookworm infection (2.3%) than Kato's thick smear in the area where there is low Soil transmitted helminthes, we recommend using Simple or Kato's thick smear to determine the prevalence of parasitic infection due to these techniques being able to detect various groups of parasites, and being inexpensive and less time consuming.

Determination of lead toxicity in Culex quinquefasciatus mosquitoes in the laboratory.

Laboratory investigations were carried out to study the effects of lead toxicity and lead uptake on Culex quinquefasciatus mosquitoes. Three different concentrations of lead nitrate were used in laboratory tests (0.05, 0.1, and 0.2 mg/l). An atomic absorption spectrometer (AAS) was used to the determine lead concentrations. The results showed that lead significantly reduced hatching, egg-production, and emergence rates, compared with the unexposed group (p < 0.05). The ratio of female to male offspring was 3.64:1, which was observed in the second generation, after the parents were exposed to 0.2 mg/l lead. No effects were observed on oviposition preference, larval weight, or larval deformation. The LC50 of lead against Cx. quinquefasciatus larvae within 24 hours was 0.18 mg/l. There was a significant increase in lead uptake related to increased lead exposure in mosquito larvae (p < 0.05). The bioconcentration factor (BCF) showed that the lead concentration in the larvae was 62 times greater than in the water. The lead concentration from parents to offspring reduced in the first and second generations (p < 0.05). There was no significant difference between female and male mosquitoes in lead concentration (p > 0.05).

A survey on malaria in mobile Cambodians in Aranyaprathet, Sa Kaeo Province, Thailand.

A cross-sectional survey of the malaria prevalence among mobile Cambodians in Aranyaprathet, at the Thai-Cambodia border, was conducted in November 2000. A total of 666 asymptomatic, mobile Cambodians who worked as traders and laborers were studied. The overall prevalence rate was 2.4%, with 93.75% of the infections being due to Plasmodium vivax and 6.25% due to Plasmodium falciparum. Almost all cases had low level of parasitemia (1+) and no sexual stages were found. Factors associated with malaria infection included being male, being in the 10-59 year age group, having a lower level of education and frequent trans-border crossing. Both groups of migrant workers (traders and laborers) had an equal chance of infection.

Septic shock secondary to scrub typhus: characteristics and complications.

Scrub typhus is an acute febrile illness caused by infection with Orientia tsutsugamushi transmitted by the bite of larval trombiculid mites (chiggers). A prospective study was conducted in septic shock patients in Maharat Hospital, Nakhon Ratchasima Province, Thailand, from 12 November 2001 to 5 January 2002. Of the 51 septic shock patients studied during the 7 week period, 18 (35.3%) were found to have evidence of scrub typhus infection; 3 patients (16.7%) died. In this study, septic shock caused by Orientia tsutsugamushi is the most prominent (35.3%) in endemic area of scrub typhus. Scrub typhus with septic shock patients results in organ failure: respiratory failure, DIC were predominant, followed by renal and hepatic involvement. Two deaths were due to respiratory failure and one death was as a result of combined respiratory and renal failure. Fever was the most common symptom, followed by headache, myalgia and dyspnea; lymphadenophathy and eschar are common signs. Laboratory findings revealed that almost all of the patients had a mild leukocytosis, reduced hematocrit and thrombocytopenia; SGOT, ALP, direct bilirubin (DB), total billirubin (TB), BUN, Cr were elevated; hypoalbuminemia was noted. Urinalysis showed that 88.9% of the patients had albuminuria. 77.8% of patients had abnormal chest X-rays.